Portable devices, such as mobile phones, tablet devices, digital cameras, and other types of computing and electronic devices can include a biometric authentication sensor that a user can simply touch with a digit, such as a thumb or finger, to access a device. A biometric authentication sensor is typically positioned offset relative to the integrated display of an electronic device, and the display lens that covers the display extends over the sensor area offset from the display. However, the display lens is designed with an opening to accommodate access to the biometric authentication sensor so that a user can place a digit, such as a thumb or finger, on the sensor, which then images the biometric input sample for user authentication.
A biometric authentication sensor needs to first be activated to image the biometric input sample, such as requiring the user to initiate a device on-button, or other type of activation of the device, which then initiates activation of the biometric authentication sensor. This type of sensor activation can include “wake on finger touch” to “wake-on” the biometric authentication sensor, which requires the sensor to always be in a powered or semi-powered state monitoring for a sensor touch. This can contribute to drain the battery or other power source of a portable device.
When a user registers multiple biometric input samples in a biometric authentication system, the matching system may take longer to acquire a match if it searches multiple stored biometric templates. Additionally, the matching system can take longer if the user digit, such as a finger or thumb, is placed on the sensor in a position or orientation that is different from that used when it was initially enrolled. If the system can determine the appropriate biometric template to match, as well as its expected orientation, then the matching process will be efficient and optimal.